<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>流程控制和循环语句</title>
</head>
<body>


</body>

<script>
    let a = 5;
    if (a>6&&a<5){
        document.write("666")
    }else if (a<2){
        document.write("777")
    } else {
        document.write("888")
    }
    document.write("<br>");

    switch (a) {
        case 1:
        case 2:
        case 3:
            document.write("123");
        case 4:
        case 5:
        case 6:
            document.write("456");
    }
    document.write("<br>")

    //for循环
    for (let i=1;i<=5;i++){
        document.write(i)
    }


</script>
</html>